regular expression for unicode

[tharhan]

i want to write a regular expression that accept all java identifier charchters

for the time being, str.match([a-zA-z]\\w*); is fine with me.

but i need to make it accept other java identifiers like underscore and NON_ENGLISH charchters

for english_arabic java identifiers i could use:
str.match([a-zA-zء-ي][a-zA-zء-ي0-9]*);

but what about other languages ?

pls help